Azco is in fact the manufacturer of the EXT 120. Longevity Resources has exclusive rights for distribution of the unit since they own the patent for the unit. The POG is indeed the same unit as the EXT 50. Azco does not do direct marketing of their products to consumers. They are primarily commercial water ozonation manufacturers that have been in that business for 25 years and sell their products through distributors like myself, Longeveity Resources and few others. I don't think you'll ever see the POG or the G2(EXT 120) on Azco's website. I can get the EXT 120 for you, but I still have to purchase it myself from Longevity.
Hope this explains all the confusion.